Anti-bounce lock



Nov. 27, 1962 F. A. NOVOTNEY 3,065,868

ANTI-BOUNCE LOCK Filed Feb. 17, 1959 3 Sheets-Sheet l \o In 0e far FrarziflJVovolneg Zyfarler a? Karla" Nov- 27, 1962 F. A. NOVOTNEY. 3,065,868

ANTI-BOUNCE LOCK Filed Feb. 17, 1959 5 Sheets-Sheet 2 jnvenzor Iran? .I. JVavatn ey Nov. 27, 1962 F. A. NOVOTNEY ANTI-BOUNCE LOCK 3 Sheets-Sheet 3 Filed Feb. 17, 1959 IIIIIIlIIIIIlI/IIIII z dr%r cZfdf/) 3,655,868 Patented Nov. 27, 1962 fhre 3,tl65,868 ANTI-BQUNCE LQQK Frank A. Novotney, Streator, lllh, assignor to Anthony Company, Streator, Ill, a corporation of lilinois Filed Feb. 117, 1959, Ser. No. 793,862 8 (Ilaims. (Cl. 2147'7) This invention relates to a vehicle gate. It has particular application to a vehicle gate which is provided or associated with means for raising and lowering the gate. It has for one object to provide latching means whereby movement of the gate is controlled and whereby unsatisfactory or undesired operation is prevented.

Another object is to provide means whereby the gate is held or latched in an elevated position in which it is retained without the continual exertion of raising energy or power applied to the gate raising means.

Other objects will appear from time to time during the course of the specification and claims.

The invention is illustrated more or less diagrammatically in the accompanying drawings wherein:

MG. 1 is a rear view of a gate to which the device of the invention has been applied;

FIG. 2 is a vertical section taken at line 22 of FIG. 1 and showing parts in elevation;

FIG. 3 is a perspective view showing the gate framework raised and latched;

FIG. 4 is an exploded view showing the g ate latching mechanism in position on the body sills;

FIG. 5 is a perspective view of the latching mechanism at one end with the parts in latched position;

FIG. 6 is a side elevation of the latching means at one end of the device, showing the parts in latched position;

FIG. 7 is a side elevation similar to FIG. 6 showing the parts in unlatched position;

FIG. 8 is a diagrammatic showing of a hydraulic system suitable for use in connection with the piston and cylinder illustrated;

FIG; 9 is a perspective of the various control lever positions; and

FIG. 10 is a partial side view, similar to FIG. 2, with the parts in a different position of operation.

Like par-ts are indicated by like numerals throughout the specification and drawings.

The device of the invention comprises a latching means and a safety latching means. It is illustrated in connection with a tail gate applied to a vehicle and arranged with power means for raising the gate so that it acts or may act to raise a load from a position below the vehicle floor, or load it from the vehicle floor to a position below. It acts, "when in the position of FIG. 2, as a tail gate closing the vehicle body. Only so much of the body and gate raising and lowering mechanism will be described as is essential for an understanding of the latching means.

As shown, the device is applied to an automotive truck upon which an engine, not shown, is mounted. The truck includes a frame having side members ll upon which are mounted body sills 2. Secured to or supported upon the sills are transverse body frame members 3. Body fioor means 4 are mounted upon the frame members. A tail gate 5, which may be of any desired construction, is movably mounted at the rear of the body. It may be made in almost any desired fashion or construction. Under present practice it will generally be made of metal of suitable frame and plating members. Thus, the gate 5 includes a surface-forming member to which the numeral 5 is directed in the drawing of FIG. 2. A frame memher 6 at the hinged edge of the gate, and a frame memher 7 at the opposite edge of the gate, together with side frame member 8, only one of which is shown in FIG.

2 2, complete the main essential elements of the gate. A bumper or positioning member 2 acts as a stop. It may have yielding parts on it, and if so it will cushion the movement of the gate when it is moved into contact with an abutment lit. The abutment 10 is carried by any desired part of the hinge and framework structure by means of which the gate itself is supported. The effect of the contact between the members 9 and 10, when they are present, is to place the gate linkage under compression and to prevent vibration when the gate is in the closed position and the vehicle is moved. If desired, the members 9 and it maybe omitted. Preferably, although not essentially, some form of gate locking or latching means is provided. This would have the effect of latching or locking the gate 5 to the bodyfor example, to the body side or wall parts 11.

Hydraulic means are provided for raising and lower-.

ing the gate. Pressure fluid from any suitable source on the vehicle which carries the gate is supplied to the cylinder 12 through a conduit 13. The cylinder is provided with trunnions 14, 14 which are mounted in bearings l5, 15 carried from a transverse frame member. As shown, the transverse frame member comprises an upper portion 16 and a lower and generally vertical portion 17. The transverse frame member is secured to the truck or vehicle frame members by bolts 18, or otherwise, as shown particularly in FIG. 1.

The cylinder 12 carries within it a piston 12a from which a piston rod 19 extends. The piston rod is secured to a crosshead 2d. The crosshead 29 is pivoted, as shown in FIG. 3, between frame members 21 of the gate-moving structure or assembly. The frame members 21 are secured at one end to a transverse member 22 and at their other ends to another transverse member 23.

The transverse frame member 22 is secured, as shown primarily in FIG. 3, to a pair of arms 24. These are of telescopic shape and arrangement and include portions 25 which are pivotally supported from the main transverse frame member l7 by bearings formed or supported in webs 26. Inserts 27 fit within the arms 24 and 25 and are secured to one or the other of them. They serve as guides and stilfeners for the telescopic sections 24 ani 25.

At the free ends of the arms 24 are mounted curved connecting members 24a which are pivoted, as at 24b, to the gate frame.

A second pair of arms, which is nontelescopic and of fixed length, is positioned outside of the telescopic arms 24, 25. This second pair of arms comprises members 28 pivotally supported to the transverse main frame member 17 between webs 29. Precise details of the pivotal support of the members 25 and 28 upon their respective webs are unimportant. In each case the web 2.6 or 29 is engaged by pin 30 or 31, respectively, so that the arms 28 may swing with relation to the frame. At their free ends the arms 28 are provided with curved portions 32 which are pivotally connected, as at 33, to a gate frame member by means of a flange 34 which forms part of the gate structure, or is secured to it.

The pivot points 31 of the arms 28 are above the pivot points 30 of the arms 25, 25, and the pivot points 24b of the arms 24 are offset also with respect to the pivot points 33 of the arms 28. This relationship is shown clearly in FIG. 2. All of the arms 24 and 28, as shown in FIGS. 1 and 2, are of round cross section. As shown in FIGS. 5, 6 and 7, the arms 28 are of angular cross section. It is immaterial for the purposes of this invention whether the arms are round or angular in cross section. The latch mechanism of the invention may be equally well applied in either case.

Two-part latch means are provided to hold the gate in raised position. As shown, these latch means include" hooks or hooklike parts and 36. The member 35 is provided with a laterally extending portion 37.

Extending upwardly from the vehicle frames 1, and preferably secured to them, and if desired also to the vehicle sills 2, are supporting plates 38 and 39. Each includes a stop portion 40 to limit in one direction the movement of the hook-engaging latching parts. While these parts are generally similar to each other, they are not identical. Each is mounted upon a control shaft 41. As shown in FIG. 1, the latch 42 is secured to the shaft 41 and the latch 43 is also secured to that shaft. The latch 42 has pivoted to it a member 44 which is biased by a spring 45 to move in counterclockwise direction, as shown in FIG. 7, toward a stop 46 carried in the member 42. The member 44 may contact the part 37 of the latch 35, as shown in FIG. 7, or may ride above it, as shown in FIG. 5. A spring 47 is secured at one end to the plate 38, as at 48, and at its other end is secured to the latch 42, as at 49. The spring acts as a return spring and is biased to move the latch 42 in the hook-engaging position.

The hooklike latch members 42 and 43 are, as stated above, mounted upon the shaft 41, being pinned thereto. Spacers 50, and similar elements, may be used if desired. The members 42 and 43 can conveniently be pinned to the shaft 41.

Mounted for rotation also in the plates 38 and 39 is an operating shaft 51. It passes through the plates 38 and 39 and is additionally supported at 52, 52 in bearings which are themselves carried by members 53, which may be supported from the transverse frame 3. At each exposed end of the shaft 51 is an operating handle 54 which is mounted in a hub 55 and pinned, as at 56, to the shaft 51. By means of the shaft 51 and the operating handles 54 the latch mechanism may be controlled from either side of the device, that is to say from either side of the vehicle upon which it is mounted. It is to accomplish this that handles are provided at each end of the shaft 51. This is a convenience and not an essential feature of the invention.

Secured to the shaft 51 is a downwardly dependent latch-moving lever 57, shown generally in FIG. 1 and in detail in FIG. 5. It is provided adjacent its free end with a lateral extension 58 and a second lateral extension 59. As shown particularly in FIG. 5, but also generally in FIG. 1, the extension 58 lies in line with a portion of the hook 43 and can be moved to contact it. Pivotally mounted on the extension 59 is a member 60 which is provided with a laterally bent end 61. A spring 62 is positioned about the member 59 and contacts the member 60. A stop 63 is fixed to the plate 39 and may be provided with an adjusting screw 64. It is positioned to be contacted by the cooperating end 65 of a stop which is carried from a collar 66 adjustably positioned on the shaft 51. A lock screw 67 may be provided in the member 66 to permit securing that member, and consequently the stop 65, in the desired adjusted position.

Secured to the frame members 21 are latch parts 68. They project upwardly, as shown generally in FIG. 1, and in particular in FIG. 3. Secured to the shaft 41 are latch members 69 arranged to cooperate with the latch member 68. The latch members 69 have angularly shaped cooperating face members 70 which fit together with the latch parts 68, as shown particularly in FIG. 3. The shape of the member 70 is such that relative swinging movement of the parts in one direction is limited.

FIG. 8 illustrates schematically the hydraulic system by means of which the piston 12a is moved. The cylinder 12 is connected at one end by a conduit 74 to a control valve housing 71. A conduit 75 connects the control valve housing to the cylinder 12. A conduit 76 leads to a pump, not shown, and a conduit 77 leads to a reservoir or sump. A valve member 78 is positioned within the housing 71 and may be moved to direct pressure fluid into either end of the cylinder 12 as desired. When the valve is in adjusted position to direct pressure fluid to one end of the cylinder it is in proper position to permit pressure fluid to be discharged from the other end of the cylinder to the reservoir or sump. As shown in FIG. 8, pressure fluid from the pump is being discharged in the direction of the arrow b and pressure fluid is being exhausted from the cylinder through the conduit 74, the piston being moved to the left. When the valve is in the dotted line position of FIG. 8 the opposite conditions prevail and pressure fluid is being directed from the pump in the direction of the arrow a and the piston is being moved to the right.

The control means for operating the valve are shown diagrammatically in FIGS. 1 and 2. They include, in addition to the valve mechanism just described, the lever 73 fixed to the shaft 51 and the linkage '72, by means of which the valve 78 is rotated to the desired position of adjustment.

When the parts are in the closed position of FIG. 2, the members 68 and 69 are in contact with each other, as shown in FIG. 2, and they act thus as safety latches. They act also as road shock arresters. When the gate is closed, as shown in FIG. 2, and the vehicle is driven down the road, inevitably shocks and jars occur and are transmitted to the gate mechanism. The safety latch construction comprising the pairs of members 68 and the pairs of members 69 in cooperation with them fit tightly together and reduce or largely eliminate the transmission of road shocks to the gate elevating and closing mechanism. They thus serve to protect the gate mechanism from road shock.

Another important feature of the invention is that the entire gate assembly cannot be lowered until the gate or platform itself has been opened. For example, in FIG. 2 the gate is shown closed. The latching arrangement 35, 36, 42 and 43 is engaged so that the entire assembly is mechanically held in the up or raised position. The main power cylinder 12 may be inactive. In this condition, if the latching arrangement 35, 36, 42 and 43 was to be released, the entire gate assembly would drop by gravity and could seriously injure the operator or bystanders. This might happen if the operator inadvertently moved the control lever 54 incorrectly when the gate was up and closed, as shown in FIG. 2.

The control handle 54 may be moved into a number of positions to cause various operations of the gate. An example is shown schematically in FIG. 9. When the gate is up, latched and closed, as shown in FIG. 2, the operator first moves the control handle from neutral to the Raise position and the gate will open by swinging down to the FIG. 6 position. The operator then keeps control of the handle in the Raise position and the gate will be lifted slightly above the floor level of the truck but will be kept level, such as shown in FIG. 7. This is desirable so that the hooks 35 and 36 will be slightly raised up off of the latches 42 and 43.

Then the operator should push the handle to the Latch Release position, shown in FIG. 9. This will rotate the latches from the position of FIGURE 6 to the FIGURE 7 position causing the latches to be fully disengaged from the hooks. The operator then moves the handle into the Lower position to lower the gate to the ground, as shown in FIG. 1.

With the gate up, latched and closed, as shown in FIG. 2, the operator might inadvertently move the control handle too far forward to the Latch Release position when he intended the Raise position at the start of this sequence of steps. This could cause the latches to release immediately and the entire assembly could drop before the gate was opened. Damage to the mechanism and injury to personnel might result.

But by my invention this is prevented. When the gate is closed, as shown in FIG. 2, the striker bars 68 move up to the position, shown in FIG. 2, where they engage the lower end of the arresters or rider assembly 69 on the latch shaft 41. If the operator inadvertently moves the control handle 54 to the Latch Release position, the arresters 69 would try to rotate counterclockwise in FIG. 2. But their slanting surfaces 70 are in engagement with the striker bars 68 and will prevent movement of the arresters 69. In effect, the control handle 54 cannot be moved to the Latch Release position while the gate platform is closed. But if the gate platform has been first opened to the position shown generally in FIG. 7, the inner arms 24 will have telescoped downwardly and the striker bars 68 will have moved down out of contact and out of the Way of the upper member 69, as shown in FIG. 10. Thus, with the gate opened but in the up or raised position, the operator can move the control handle to the Latch Release position to release the latch mechanism 35, 36, 42 and 43. Then the gate, under power, may be lowered. In this sense, my invention provides a safety latch or linkage or interlock which will prevent the gate from being suddenly released when in its closed position, as in FIG. 2. The interlock prevents the gate from dropping by gravity resulting in damage to the gate and injury to personnel.

In addition to being an arrester for road shock, the invention will also prevent the latches from being released at the wrong time. In short, the latches cannot be released until the gate has been opened. The arrangement prevents the latches from disengaging should the operator exert additional pressure on the handles during opening of the gate.

The use and operation of the invention are as follows:

The general gate structure as disclosed herein is in many respects identical with the general gate construction shown in Patent 2,684,770, issued to Park, and Patent 2,654,491, issued to Duis and Park. The former is directed to a latch structure and the latter is directed to the general gate and gate elevating and closing mechanism. The novelty of the present construction resides in the latch mechanism with the gate.

The gate is carried on two pairs of arms, the arms 28 being of fixed length and the arms 24, 25 being telescopic and hence of variable length. The two pairs of arms are pivoted to a cross member which is itself secured to a vehicle frame and the arms are pivoted also to a gate. The hydraulic piston and cylinder assembly is pivotally mounted on the same frame member upon which the arms are mounted. When pressure fluid from any suitable source is supplied to the piston and cylinder assembly movement of the piston and of the gate is accomplished. The piston is connected to the gate. In the particular forms shown, when the piston is caused or permitted to move outwardly, the gate is lowered. It finally reaches the position of FIG. 1, which is essentially in contact with or close to the ground surface upon which the vehicle which carries the gate stands. When pressure is applied to the cylinder to move the piston inwardly, the piston rod is withdrawn inwardly and the gate is raised. It is carried to a horizontal position-for example, as shown in FIGS. 6, 7 and 10.

When it is desired to close the gate so that it will stand vertically as shown in FIG. 2, the piston and cylinder assembly is manipulated to accomplish that movement.

Latch means are provided to hold the gate in the raised position. These means include hooks 35 and 36 on the arms 28, and movably mounted latches 42, 43. When the gate is in the raised position the latches may engage the hooks as shown, for example, in FIGS.

and 6. Spring means, such as the spring 47 of FIGS. 1 and 6, may be present to bias the latches into latching engagement with the hooks.

'When the gate is latched in the raised position and is horizontal, as shown in FIG. 6, if it is desired to close it by moving it to the vertical position of FIG. 2, the controls are so manipulated that the gate remains latched. Pressure, in what may be called the lowering direction, is then applied to the piston. If the gate were. unlatched,

pressure on the piston to move it outwardly with respect to the cylinder would cause the gate to be lowered. Since, however, the gate is latched it cannot be lowered and the pressure to move the piston outwardly in the so-called lowering direction will accomplish movement of the gate from the horizontal position of FIGS. 6 and 7 to the vertical position of FIG. 2. As this movement occurs the telescopic .arms 24, 25 are expanded and their length is extended. It is this telescopic feature which permits the movement of the gate to vertical position. As shown in FIG. 1, the arms 24, 25 are not extended because the gate has been moved to the lowered position at a time when it was not latched, and thus held in the upper position. As shown in FIG. 2, however, the telescopic arms 24, 25 are in the extended or expanded position and have been extended to cause the rotation of the gate toward the vertical position.

The gate of Patent No. 2,654,491, issued to Duis et al., operates in the manner described and to accomplish all of the results thus far mentioned.

Only so much of the structure as is necessary to understand the operation and advantages of the latches is illustrated. Control means are provided for controlling the movement of the pressure fluid to accomplish the raising, lowering and closing of the gate thus described. They include control means substantially like those shown in Duis et a1. Patent'No. 2,654,491, and they provide means for introducing pressure fluid to either end of the cylinder selectively to cause the piston to move in one or the other direction along the cylinder. The control means are illustrated in FIG. 8.

Means for operating and controlling the latch mechanism are shown and will be described below.

A control shaft 51 extends substantially from side to side of the body with which the gate is associated and at each end it has an operating handle by means of which it may be moved to control the latching and unlatching. If convenient, the pressure fluid controlling means may be associated with this control.

A latch-operating shaft 41 is mounted for rotation adjacent the shaft 51. As shown particularly in FIG. 1, the shaft 41 stands directly behind the shaft 51 in the direction of the gate and in part obscures the shaft 51. It is mounted for rotation and the latch members 42 and 43 are fixed to it and hence are rotated with it. The striker bars 68 and 69 are also fixed to the latch control shaft 41.

A lever 57 is fixed to the shaft 51 and through it movement of the shaft 51 may be effective to move the latches. Stop means may be provided for the shaft 51, as shown in FIG. 5 in particular. As shown particularly in FIG. 1, but also as shown in FIG. 5, the lever 57 is provided with an extension 53 which may contact the latch 43. Thus movement of the shaft 51 will carry the lever 57 and when that lever moves in clockwise direction from the position shown in FIG. 5, it may move the latch 43 in the unlatching direction when the parts are free to permit this movement. Rotation of the control shaft 51 may thus, by the action of the lever 57, move the latch 43. Since the latch 43 is fixed to the latch shaft 41 movement of the latch 43 will rotate the shaft 41 carrying with it the four latches which are secured to it, namely the latches 42, 43 and 69.

The pivotally mounted safety latch member 66, which is carried by the lever 58 has .a lateral extension 61 which may be moved to contact the latch 43, preventing movement of the latch structure.

The members 68, which may be called latch members or striker members, are fixed to that part of the telescopic arm assembly which moves when relative movement of the parts 24 and 25 occurs. The parts 68 are mounted, as shown in the several figures, for example FIGS. 1 and 3, on the 'frame'members 21 and these frame members are fixed in relation to the arm portions 24 which move with relation to the arm portions 25. Thus, during the extension of the telescopic parts the striker or latch members 68 move toward and away from the cooperating latch members 69. When the gate is in the fully closed or upright position, as shown in FIGS. 2 and 3, the parts 68 and 69 are in contact with each other and prevent unlatching. When the gate is in the horizontal or the lowered position the members 63 are out of line with the members 69.

When the gate is to be lowered the handle 54 is moved first counterclockwise in the direction of the arrow of FIG. 2.

The control handle 54, as shown in FIG. 2, is in the neutral position which is vertical. With the gate in the vertical position of FIG. 2 and it is desired to lower the gate first to the horizontal and then to the ground, the following sequence of operations is carried out. The handle 54 is moved in the direction of the arrow, that is to say away from the gate and toward the forward end of the truck. The movement of the handle rotates the shaft 51 and with it carries the lever 57 which contacts the movable latch member 43. At this movement the latch 43 could not be rotated because of the continuing contact of the members 68 and 69, except for the fact that the shaft 51, which is rotated by the movement of the handle 54, is connected to the valve system of FIG. 8 which controls the flow of pressure fluid to and from the cylinder 12. In the initial stages of the movement of the lever 54 the pressure valve 71 is actuated by the linkage 72 to the dotted line position of FIG. 8. The linkage 72 is connected to a lever 73 fixed on the control shaft 51 to cause pressure fluid to flow to the outer face of the piston in the direction of the arrow a of FIGS. 2 and 8 and to withdraw the piston. Thus the telescopic arms 24, 25 are somewhat telescoped and rotated partially clockwise from the position of FIG. 2 toward the lowering direction. As this occurs the members 68 and 69 are moved out of contact with each other. Thereupon continued movement of the handle 54 in the direction of the arrow of FIG. 2 and FIG. 6 unlatches the gate, as shown in FIG. 7. The contact of the lever 57 with the latch member 43 rotates the shaft 41 and carries with it also the latch 42 so that the gate is now fully unlatched and ready for complete lowering. The downward pivotal movement of the telescopic arms has moved the members 68 not only out of contact with the members 69, but sufficiently below them so that further movement of these members is uninterrupted.

After the gate has been unlatched, as just described, and as shown in FIG. 7, the lever 54 is rotated in the reverse direction, as indicated by the arrow, and pressure fluid, as in FIG. 8, is directed to the inside face of the piston in the direction of the arrow b of FIGS. 2 and 8. Continued exertion of pressure in this direction carries the piston and the piston rod to the right, as viewed in FIG. 2, and causes complete lowering of the gate to the position of FIG. 1.

As the direction of rotation of the handle 54 is reversed, as just described above, the latches 42 and 43 are held out of engagement with the fixed hooks 35 and 36 by reason of the contact of the extension 58 of the lever 57 with the member 43. When this occurs the member 44 carried by the member 42 contacts the stop extension 37 of the fixed latch 35 and prevents return movement or swinging of the latch members 42 and 43 into engagement with the fixed hooks 35 and 36.

In addition to being an arrester or absorber for road shock, the arrangement will also prevent the latches from being released when the gate is closed. In effect, the latches cannot be disengaged until the gate has been opened. This in turn prevents the gate from dropping half way to the ground or further and possibly causing damage or injury to personnel.

As the control lever 54 is put into raise position, the valve is opened and allows oil to flow from the pump to the top end of the cylinder, This will be the upper end when the cylinder is raised and the gate is closed, as shown in FIG. 2. Now if the mechanism stays on the latches, the gate will be opened. There is, however, a tendency for the gate arms to be lifted slightly from the latches because of the direction of the cylinder force as the piston is moved inwardly away from the outer end of the cylinder. If the cylinder moves slowly enough there will be less tendency to cause this lifting oif of the latches.

During this phase of the operation there is an additional force which tends to raise the gate mechanism or gate arms slightly off of the latches and this is due to the position of the gate platform itself. In general when the gate platform is in the raised and closed position its center of gravity is to the right of the point 33 as shown in FIG. 2. As the gate is opened it pivots initially about the point 33 and is helped in this pivoting movement by the fact that the center of gravity at this stage of the operation is to the right of point 33 as seen in FIG. 2. When the gate has been opened slightly the center of gravity is then to the right of the point 24b and there is a further tendency for the gate platform to pivot downwardly about the point 24b and thereby to raise the point 33 slightly. The effect of this is to accelerate the raising off of the latches. Due to the weight of the platform and its force on the piston, which is of course connected to it through the platform-carrying arms, oil enters the cylinder much more readily, and thus at an accelerated rate.

All of the factors just mentioned act in the same direction and cause the entire mechanism to raise off of the latches at the initial stage of the lowering movement. Due to the weight of the gate and to the gate-supporting mechanism, including the gate carrying arms, the latch mechanism might not otherwise be opened by hand because the weight of the structure would tend to hold the latches in tight engaging contact. The structure of the invention thus additionally assists in proper opening and unlatching of the gate mechanism when the controls are operated in the unlatching direction.

While I have shown and described the preferred form and suggested several variations of my invention, it should be understood that suitable additional modifications, changes, substitutions and alterations may be made without departing from the inventions fundamental theme. I, therefore, wish that the invention be unrestricted except as by the appended claims.

I claim:

1. A tailgate assembly for a truck or the like, comprising a support adapted to be mounted on the truck chassis, a tailgate platform, lifting means on the support connected to the platform and arranged, when actuated, to raise the platform from a lowered position to a raised position substantially level with the truck body, said lifting means being effective to move the platform generally about its inner transverse edge from a generally horizontal disposition in its raised position to .a generally vertical upward disposition in a truck closing position, power means for actuating said lifting means, latching means for releasably holding the platform at its truck closing position and an interlock between the lifting means and the latching means to prevent the platform from being moved to its lowered position when the platform is in its truck closing position.

2. The structure of claim 1 further characterized in that the lifting means includes a linkage with a plurality of platform supporting members, one of the supporting members being of variable length and the other being of substantially fixed length, means for latching the platform in its raised position, said power means including a reversible power actuator connected to the support and to the platform and effective normally to apply, when moved in one direction, a raising thrust to the platform through the point of connection between the variable length supporting member and the platform, said actuator 9 being eifective, when moved in the opposite direction with the platform latched in its raised position, to vary the length of the variable length member and to tilt the platform about its inner transverse edge.

3. The structure of claim 1 wherein said power means includes a reversible power actuator operatively connected to the support and to the lifting means effective normally to apply, when moved in one direction, a raising thrust to the lifting means and platform and, when moved in the opposite'direction, to apply a lowering thrust to the lifting mean and platform.

4. A tailgate assembly for a truck or the like, comprising a support adapted to be mounted on the truck chassis, a tailgate platform, lifting means on the support connected to the platform and arranged, when actuated, to raise the platform from a lowered position to a raised position substantially level with the truck body, said lifting means being effective to move the platform generally about its inner transverse edge thereof from a generally horizontal disposition in its raised position to a generally vertical upward disposition in a truck closing position, power means for actuating said lifting means, and shock absorbing abutting interlocking members between the lifting mean and the truck to eliminate up and down movement of the platform when the truck is in transit.

5. The structure of claim 4 wherein said power means includes a reversible power actuator opera-tively connected to the support and to the lifting means effective normally to apply, when moved in one direction, a raising thrust to the lifting means and platform and, when moved in the opposite direction, to apply a lowering thrust to the lifting means and platform.

6. The structure of claim 4 further characterized in that the lifting means includes a linkage with a plurality of platform supporting members, one of the supporting members being extensible and the other being of substantially fixed length, means for latching the platform in its raised position, said power means including a reversible power actuator connected to the support and to the platform and effective normally to apply, when moving in one direction, a raising thrust to the platform through the point of connection between the extensible supporting member and the platform, said actuator being effective, when moving in the opposite direction with the platform latched in its raised position, to extend the extensible member and to tilt the platform about an axis passing through the point of connection between the member of fixed length and the platform.

7. The structure of claim 4 further characterized by and including latching means for holding the platform in its raised position, the interlock being also associated with the latching means to prevent it from unlatching when the platform is in its truck closing position.

8. The structure of claim 7 further characterized in that the latching means is, at least in part, on the lifting means.

References Cited in the file of this patent UNITED STATES PATENTS 2,654,491 Duis et al. Oct. 6, 1953 2,754,143 Huehnel July 10, 1956 2,837,227 Lugash June 3, 1958 

